European Biophysics Journal

, Volume 46, Issue 1, pp 59–64

Osmosis and thermodynamics explained by solute blocking

Original Article

DOI: 10.1007/s00249-016-1137-y

Cite this article as:
Nelson, P.H. Eur Biophys J (2017) 46: 59. doi:10.1007/s00249-016-1137-y


A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.


Osmosis Thermodynamics Kinetics Aquaporin Colligative properties Controversy 

Funding information

Funder NameGrant NumberFunding Note
National Institutes of Health
  • GM20584
National Science Foundation
  • 0836833

Copyright information

© European Biophysical Societies' Association 2016

Authors and Affiliations

  1. 1.Department of PhysicsBenedictine UniversityLisleUSA

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